Oxymorphone hydrochloride, also known as 4,5-epoxy-3,14-dihydroxy-17-methyl-(5α)-morphinan-6-one hydrochloride (1:1), or 1,4-hydroxydihydromorphinone, (C17H20ClNO4, MW 337.80) is a semi-synthetic opioid analgesic. The chemical structure of oxymorphone hydrochloride is shown below

Oxymorphone HCl is indicated for the relief of moderate to severe pain. Oxymorphone HCl is also indicated as a pre-operative medication to alleviate apprehension, maintain anesthesia and as an obstetric analgesic. Additionally, oxymorphone HCl may be used to alleviate pain in patients with dyspnea associated with acute left ventricular failure and pulmonary edema.